1. Field of the Invention
The present invention relates to a recording apparatus which performs recording into a recording medium on the basis of recording information.
2. Related Background Art
A sheet discharge mechanism is provided in the recording apparatus such as a printer, a copying machine, a word processor, a personal computer, and a facsimile machine. The sheet discharge mechanism discharges the recording medium (hereinafter, it may be referred to as recording sheet) such as a recording paper in which the recording has been performed on the basis of the recording information (image information or the like) to the outside of the apparatus. Normally a discharge tray (sheet discharge tray unit) for retaining the discharged recording sheet is provided in the sheet discharge mechanism.
FIG. 23 is a schematic perspective view illustrating the state in which the sheet discharge tray is drawn in the conventional recording apparatus, FIG. 24 is a schematic side elevation for explaining a technical problem of the sheet discharge tray in the conventional recording apparatus, FIG. 25 is the schematic perspective view showing the state in which the front cover is closed in the conventional recording apparatus, and FIG. 26 is a schematic longitudinal sectional view mainly showing a structure of the tray accommodation unit of the lower case in the conventional recording apparatus.
In FIGS. 23 to 26, the recording apparatus includes a lower case 18, an upper case 19, an access cover 27, a sheet discharge unit, and a printer unit (not shown) which is accommodated inside an exterior case of the apparatus. As shown in FIG. 23, the sheet discharge unit includes three components of a first sheet discharge tray 20, a second sheet discharge tray 21, and a third sheet discharge tray 22. Each of grooves or ribs is formed on both sides of the sheet discharge trays 20, 21, and 22, and the sheet discharge trays 20, 21, and 22 engage one another. Therefore, the sheet discharge trays 20, 21, and 22 are mounted on a main body of the apparatus while being slidable along one another. The sheet discharge trays 20, 21, and 22 can be drawn from the main body of the apparatus. The sheet discharge trays 20, 21, and 22 are accommodated in the tray accommodation unit of a bottom portion of the lower case 18 in non-use.
Pawls (not shown) formed in left and right points in a rear portion of surface of the first sheet discharge tray 20 are configured so as to be able to fit to the pawls formed in the left and right points in front and rear portions of tray accommodation unit of the lower case 18. Ribs having concave and convex portions are formed in the front portion of a backside of the first sheet discharge tray 20, and the ribs can fit to concave portions formed in the left and right points in the front and rear portions of the backside of the second sheet discharge tray 21. The pawls (not shown) are formed on the left and right sides in the front and rear portions of the backside of the second sheet discharge tray 21, the pawls (not shown) are also formed inside grooves 22a and 22b formed on the left and right sides the surface of the third sheet discharge tray 22, and the pawls fit to one another.
In the above configuration, at first a front cover 27 is rotated to expose a sheet discharge outlet (opening portion) in a front face of the recording apparatus in performing the recording (printing). At this point, the front cover 27 is retained in a predetermined angle by tray rails fixed to the lower case 18 while maintaining an appropriate gap from a floor surface (loading surface) on which the recording apparatus is installed. When an operator places operator's finger on a handgrip portion 22c formed in the front portion of the third sheet discharge tray 22 to pull the third sheet discharge tray 22, the second sheet discharge tray 21 and the first sheet discharge tray 20 are sequentially drawn from a main body of the apparatus to a predetermined length by the pawls, and then the second sheet discharge tray 21 and the first sheet discharge tray 20 are retained and fixed in the state shown in FIG. 23. A height of a front end of the third sheet discharge tray 22 is maintained at a height position substantially equal to a sheet discharge path in such a manner that a bottom surface of the first sheet discharge tray 20 abuts on height adjustment ribs (not shown) of the front cover 27. Thus, the recording sheet which is of the recording medium discharged from the recording apparatus is sequentially stacked on the sheet discharge tray unit.
When the recording (printing) is finished, the third sheet discharge tray 22 is moved backward to release the fitting between the pawls, the second sheet discharge tray 21 and the first sheet discharge tray 20 are sequentially retracted, and the sheet discharge tray unit including three sheet discharge trays is accommodated in the tray accommodation unit of the lower case 18. In an inkjet recording apparatus in which the recording is performed by ejecting ink from recording means to the recording medium, when discharge speed of the recording sheet discharged from the recording apparatus is increased in order to increase recording processing speed, because the next recording sheet is stacked before the ink of the previously recorded recording medium (recording sheet) is not dried, sometimes there is generated a problem that the previously discharge recording sheet is soiled by the ink of the subsequently discharged recording sheet or the recording ink (adhesion ink) is rubbed.
In order to solve the problem, it has been proposed that the discharged recording sheet is retained (the recording sheet is bent) while curvature is given by forming a shape of the front end of the third sheet discharge tray 22 in an arcuate shape, thereby the ink soil of the previously discharged recording sheet is prevented. The discharge can be also performed to the recording sheet having higher rigidity in such a manner that the front end height of the third sheet discharge tray 22 substantially corresponds to the sheet discharge path of the recording apparatus, and the front end portion of the recording sheet can be preventing from catching in discharging the recording sheet. Therefore, in order to secure sheet discharge function (sheet discharge performance), it is necessary to precisely keep the curvature of the front end shape of the third sheet discharge tray 22 and the retaining attitude (height) in drawing the sheet discharge tray within predetermined values. Japanese Patent Application Laid-Open No. 2003-054070 can be cited as an example of a patent reference disclosing the above-described conventional technology or similar technology.
In the conventional recording apparatus, when the recording apparatus is not used, the recording apparatus adopts means for accommodating the sheet discharge tray unit in the bottom portion of the main body. However, since the front end portion of the third sheet discharge tray 22 has the curvature, there is a limitation in the vertical direction, and there is the technical problem that the sheet discharge tray unit can not be completely accommodated in the tray accommodation unit of the lower case 18. Further, as shown in FIG. 26, in order to decrease the height of the main body of the recording apparatus, there is the technical problem that the sheet discharge tray unit is accommodated while the front end portion of the third sheet discharge tray 22 is protruded from the tray accommodation unit. Namely, in order to clearly express a front face of the recording apparatus from the viewpoint of appearance of the recording apparatus, it is necessary to adopt a technique of extending the front portion of the main body of the recording apparatus by the amount of protrusion of the front end portion of the third sheet discharge tray 22. Therefore, when the appearance is improved, there is the problem that an overall configuration of the recording apparatus is enlarged.
On the other hand, when the third sheet discharge tray 22 is fully accommodated in the tray accommodation unit in order to reduce a size in a depth direction of the main body of the recording apparatus, since it is necessary to increase the height of the main body of the recording apparatus by the height in which the front end portion of the third sheet discharge tray 22 has the curvature, there is also the problem that an overall configuration of the recording apparatus is enlarged. The retaining attitude (height) of the sheet discharge tray can be controlled in such a manner that a part of the first sheet discharge tray 20 abuts on the height adjustment rib of the front cover.
In the case where the front portion of the main body of the recording apparatus (exterior of the apparatus) has a rounded appearance, generally an outline of the front cover also has the rounded shape. As can be seen from FIG. 24, in the case where the. curvature of the front cover 27 is increased (radius of curvature is decreased), a height H1 from the floor surface to the front end portion of the front cover 27 is increased in opening the front cover 27 when compared the substantially plane-shaped front cover. The bottom surface of the first sheet discharge tray 20 abuts on the front portion of the front cover 27. As a result, the front end of the third sheet discharge tray 22 is separated upward away from the sheet discharge path by a distance H2 (the height is increased by H2), and the problem occurs when the recording sheet having higher rigidity is discharged.